1. Field of the Invention
The present invention relates to medicinal compositions commonly known as Epidermal Growth Factor (EGF)/Urogastrone, and more particularly refers to related forms of these compositions derived from yeasts and yeast extracts.
2. Description of the prior art
Naturally produced Epidermal Growth Factor was discovered a number of years ago. Relatively large amounts were found stored in mouse salivary glands. The material was given the name murine Epidermal Growth Factor(m-EGF) when it was discovered that newborn mice treated with the material opened their eyes earlier than did control mice. It was subsequently discovered that Epidermal Growth Factor was also involved in the control of gastric acid, which finding resulted from the discovery that Urogastrone was purified from the urine of pregnant women, and it was shown that this material was identical to human Epidermal Growth Factor. Epidermal Growth Factor has been found to be very effective in the healing of wounds, and particularly wounds resulting from corneal transplants and cataract surgery. The same material, also designated as Urogastrone has been found useful in the treatment of gastric ulcers.
Because naturally occurring Epidermal Growth Factor and Urogastrone are available in only minute quantities naturally, synthetic methods, including genetic engineering methods are now utilized to produce these materials. Such methods are disclosed in many patents, including the following: U.S. Patent Nos. 3,883,497, 3,948,875, 4,032,633, 4,035,485, 4,731,357, 4,743,679, 4,760,023, 4,764,593, and 4,820,690. However, these methods of producing the materials are not entirely satisfactory, as they are quite time-consuming and expensive.